Answer:
15. x = 4
17. AB = 9
Step-by-step explanation:
15.
Since B is in the middle of AC, AB + BC = AC
So,
x + 5 + 2x - 4 = 13
3x + 1 = 13
3x = 12
x = 4
17.
Since B is in the middle of AC, AB + BC = AC
So,
x + 16 + x + 17 = 19
2x + 33 = 19
2x = -14
x = -7
Going back to the question, it says to find the length of AB.
AB = x + 16 = -7 + 16 = 9
